Make list and ignore empty values?

Hello,

is it possible to make a list (via data validation) and ignore all empty values / cells?
find attached an example what i mean)

When i open the drop-box in cell C1 i also get the empty cells in the list.

I found a solution with SORT / UNIQUE / FILTER - but this only works with the newer versions Excel 365 and Excel 2021.

Is there also a solution for that using Excel 2019 or Excel 2016?